


Join me for afternoon demons?

by justabrain



Category: Doctor Who, Sherlock (TV), Supernatural
Genre: Crossover, Deductions, Gen, Superwholock
Language: English
Status: In-Progress
Published: 2014-09-19
Updated: 2014-12-01
Packaged: 2018-02-18 01:22:50
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,585
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2330084
Author URL: https://archiveofourown.org/users/justabrain/pseuds/justabrain
Summary: <blockquote class="userstuff">
              <p>What happens when the Winchesters, Castiel, the Doctor, and Clara intrude on Sherlock's afternoon?</p>
            </blockquote>





	1. The Meeting

**Author's Note:**

> I have for now abandoned working on this fic. I may eventually start it again, but that will not be for a long time. My apologies. I do still post other fics though, so feel free to check those out if you like :)

         Sherlock glanced up disinterestedly as John let three figures into their flat. Not clients. Bored, he looked back down at the slides under the microscope, but paused as he ran the men back through his mind. Something was... off about them. Slowly, trying to remain relatively unnoticed, Sherlock looked back up at them. All three were obviously American, just arrived, but why they had come all the way to London, he couldn’t quite tell yet, especially as the one in the leather jacket appeared to be still on edge, likely scared of flying. His brother, the tall one, was obviously well-read and had gone to university, from the way he was scanning Sherlock’s bookshelf. They had both grown up without their mother, but the shorter, and likely older, one did have an amulet of some kind that he was attached to. Possibly from his brother. They were obviously very close and had been living together for quite some time now, and from how he was standing, the older one was fiercely protective of his brother.

         But the third figure was different. He wasn’t related to the other two, not by blood anyway. Sherlock now realized that the aura of strangeness came from him. He seemed to not quite fit in or to perfectly obey the rules of etiquette. Actually, the more Sherlock watched him, the more he reminded Sherlock of himself. He was quite intelligent, though not in the same ways as Sherlock was. He was quite fond of the trench coat he wore, and obviously loved the man in the leather jacket, though the other seemed to either not be aware of that fact or did not reciprocate the feelings. Strangely, there was a distinct lack of personal or identifying items that he wore, but --

         “Hello, Sherlock, was it?” the leather-clad man said as he approached the kitchen and pulled out a badge. “I’m Detective Simmons, and these are my colleagues, Detectives Fehley and Bonham. We’re with the FBI and we’d --”

         “Nope.”

         “Excuse me?” ‘Detective Simmons’ said, taken aback.

         “Those aren’t your names. And FBI? With that hair?” Sherlock said, looking at the other brother. He scoffed.

         ‘Detective Simmons’ cleared his throat. “The - uh, the regulations have changed. New management and all that.”

         “Still not your names.” Sherlock looked up to see an incredulous look on the other man’s face. “You want me to believe you share names with members of one of the most famous rock bands in history and just _happen_ to be working together? And the fact that you’re obviously brothers, not the trench coat one, the other two, means you should share a last name. If you’re going to have an alias, at least make it believable.” He glanced over at John, who was looking at him with disbelief. “What?”

         “You... You listen to _KISS_?”

         “No, of course not,” Sherlock said, a little too quickly. He looked back down at his microscope. “It’s useful to know common aliases.”

         Still slightly unsettled, ‘Detective Simmons’ turned to look at his brother, with a question in his eyes. His brother shrugged, and the older one sighed. “Fine. I’m Dean Winchester and this is my younger brother Sam. We’re here because we... Uh, we think someone you know might be a demon.”

         Sherlock’s head snapped up to look at him. “You _what_?”

         At this, Sam stepped in. “What he’s saying is, we’ve been monitoring all the signs of demon activity in the US and UK and all over. Long story, don’t ask. Anyway, all the signs were there -- well, here. We don’t know what they’re doing here, but --”

         “Demons.”

         “Yes...” Sam said cautiously, wondering what the detective’s reaction would be.

         “You two are idiots. Demons don’t exist. I’d expect better from someone who went to uni.” Sam and Dean exchanged a look. Sherlock ignored them and continued. “What’s your name?” he asked the third man.

         “Ca--”

         “Calvin,” Sam interrupted. “He’s a buddy of ours.”

         John cleared his throat before Sherlock could get in a snarky comment. “Sherlock? A minute?” Quickly, he pulled Sherlock into the hallway and closed the door. “Sherlock, what if they’re telling the truth?”

         “They’re not. Demons, angels, all that supernatural nonsense, it’s ridiculous. It’s all hoaxes and illusions. They’re obviously delusional and obsessed and should be sent away for the safety and sanity of all involved.”

         “Ok, so say there’s not actually demons. There’s still something going on, otherwise they wouldn’t have come all the way from America. I say we hear them out and see if there’s something we can do to help, or at least make them think we did something.”

         Sherlock looked at his flatmate for a second, then went back into the room and sat in his armchair. John quickly followed suit. "Sit,” Sherlock said, indicating the couch. Sam and Dean obeyed, but ‘Calvin’ stayed standing, saying that he wasn’t tired, despite the time change. “What makes you think there are ‘demons’ here?”

         The brothers looked at each other. “Well, we’ve sort of grown up in this business, you know? We know the signs,” Sam said.

         “What business is that?” John asked.

         Dean spoke. “Saving people. Huntin--”

         “We hear about dangerous creatures and... _other things_ that most people don’t know about,” Sam interrupted, “and we kill them.”

         “What sort of ‘creatures’?” John said, skeptical.

         Dean cleared his throat, wary of how Sherlock had reacted a few minutes ago. “Well, uh, werewolves, vampires, ghosts, shape shifters, --” Sherlock scoffed. “--a lot of other things, and... demons.”

         “Right... So, how would we know if there was a demon here?”

         “Well, the best way to tell if one has been around recently is sulfur. Have either of you smelled any sulfur recently? Even just the tiniest bit?”

         John thought for a moment. “Well, there was something a few days ago that I suppose smelled a touch like sulfur.”

         “I was experimenting with carbon dioxide and yogurt. Something went wrong.”

         “Ah... Sorry, I guess you won’t be able to get any leads through sulfur, with Sherlock experimenting non-stop. He tends to do that when--”

         “Shh!” Sherlock suddenly cut him off. “What’s that noise?”

         “What noi--”

         “SHH! Listen...” Soon, John realized he could hear it, too, a sort of mechanical wheezing that seemed to be coming from downstairs. After a few seconds, it seemed to stop, and a few more seconds after that, voices and footsteps on the stairs. “It seems we have visitors.” Sherlock glanced at the brothers. “ _More_ visitors.”

         The room was silent as the door opened to let in a short woman with brown hair, obviously an elementary school teacher who loved kids, but had none of her own, and was unmarried with a romantic interest. As Sherlock kept observing her to see what else he could find out, a tall, lanky man in his fifties strode into the room, pointing a small device that glowed at one end at everybody in the room. Sherlock shifted his attention. He, like ‘Calvin’, was, for some reason, a bit difficult to glean any information from. It was almost like he was--

         “Not human.” The strange man had stopped in front of ‘Calvin’. “You’re not human.”

         “Dammit,” Dean muttered. “Sammy, I told you we shouldn’t have let him come.”

         “You think we could have stopped him?” Sam hissed back.

         “What are you...?” The older man said to himself, still scanning ‘Calvin’ with his pointer, which was making a strange buzzing sound. He suddenly stopped and held it up to his face to look at something on it. “No. No, that can’t be! It must be broken. I knew I should have upgraded it. That can’t be right.”

         “Dean, he’s going to find out eventually, so we might as well just tell him and save him the trouble.”

         “But--” He tried to come up with a good argument. “Fine. You do it.”

         “Doctor,” Sam started. The grey-haired man looked up. “Your screwdriver isn’t malfunctioning. That’s Cas. Castiel. We told you about him, remember?”

         “Ah, yes, and you couldn’t have been bothered to mention that he’s a bloody _angel_?!”

         “WHOA, hold on, a _what?”_ John interrupted. “A--an _angel_? As in, heaven? God’s warriors? Gabriel and Lucifer and that whole lot?”

         Finally, Castiel spoke. “Yes. They are my brothers. Along with Michael, Uriel, Ezekiel, Balthazar, Raphael--”

         Dean cut him off. “Yeah, Cas, thanks, I think we get the picture.”

         Sherlock, who had been sitting quietly in his chair observing, abruptly stood up and without a word walked to his room, closing the door behind him. The room fell silent, watching him. After a moment, John stood up as well. “Excuse me,” he said. “I’ll... I’ll go talk to him.”

         John opened the door to see Sherlock curled up on his bed with his housecoat draped around him, not moving. “Go away, John.”

         “I know this is extremely weird and doesn’t make a lot of sense, but maybe if we just hear them out and see what their explanations are, then--”

         “No.” Sherlock stood up. “Don’t you see what this is? They’re trying to make a fool of me. Make me look like I’m the same sort of gullible idiot who falls for these things. ‘Sherlock Holmes Believes in Angels! You Should, Too!’ or ‘This just in: Greatest detective in England couldn’t see practical joke was a hoax!’”

         “ _Sherlock._ Didn’t you see them? The taller one, Sam? He looked smart; you said yourself he went to uni. The old man and the girl who came in, they both looked intelligent, though the older one seemed a touch mad. And Castiel seems smart. Why would they trick you? What possible reason would they have? Half of them aren’t even British! Why could they want to humiliate you?”

         “Because they always do.”

         “Who always do?”

         “People like them.” And with that, Sherlock wrapped his housecoat back around him and flopped onto his bed, the conversation clearly over.

         Sighing, John walked back into the living room. “Sorry, he’s a bit reluctant to talk right now. He’ll be fine. Just... give him a little while. He’s not used to stuff like this, all the supernatural creatures and such.” He paused and turned to the older man and the young woman. “Sorry, what did you say your names were? Doctor, right? Doctor... who?”

         “No, just the Doctor, thanks.”

         “Oh... Ok. And you are...?”

         “Clara. Clara Oswald. And you? Military man I can see. Sorry, the Doctor didn’t tell me much about who we were meeting, just that if I liked mysteries as much as I liked meeting Robin Hood, I’d be very happy. He didn’t say anything about demons either or angels or anything and I don’t even really know who these other people are, just their names, and I’m so sorry, I just keep talking and never know when to shut up when I’m nervous.”

         John smiled. “John Watson, former captain, 5th Northumberland Fusiliers. Was a doctor, but got shot and shipped off home. Very nice to meet you. These are Dean and Sam Winchester. They apparently hunt demons and vampires and such. And the one who just stormed out of here, that was Sherlock Holmes.”

         Clara’s smile froze on her face. “Sherlock. Holmes. _The_ Sherlock Holmes? As in ‘The Hound of the Baskervilles’ Sherlock Holmes?”

         “Yes, I believe that’s what I titled one of our cases. Just don’t let Sherlock know you’re a fan. He’s not always very grateful for that sort of thing.”

         “Oh, ah, no of course not!”

            At that moment, the door to Sherlock’s room banged open, and the man walked out, heading straight for his chair, where he promptly sat down. “Tell me about this demon you’re hunting.”


	2. (Attempted) Departure

**Summary for the Chapter:**

> And they're off to find the demon! Well, almost.

"Where did you get this?" Clara asked, gingerly holding a serrated knife with a wooden handle. 

"A... friend gave it to us. It kills demons," Dean said.

"But it also kills the host. So, we try to exorcise it instead, especially if we know that the person who's being possessed is still alive and in there somewhere."

Suddenly there was a knock at the door. "Sherlock, there's a big box downstairs that says 'police box'. Do you know anything..." Mrs. Hudson trailed off as she opened the door and saw the room full of strangers.

Sherlock sighed. "Sam and Dean, Americans, Castiel, an angel, an unmarried, but dating, elementary school teacher, and a doctor of some sort." He gestured to each of them in turn. "Mrs. Hudson." 

"Clara," John said. "Her name is Clara. And that's - well, he just calls himself the Doctor."

"It's very nice to meet you all," Mrs. Hudson said. "The box... Is that...?"

"Mine," the Doctor said. "The TARDIS. She's a time machine. Space ship, too."

"Oh. Would you all like some tea?" she asked weakly. She glanced at Sam and Dean. "Or coffee?" 

Sam looked up from his computer. "Ah, no thank you," he said with a smile.

"Alright. I'll be downstairs if you need anything, Sherlock." She closed the door.

Clara laughed. "She used to this sort of thing? She didn't seem to react much to the TARDIS or Castiel."

"You could say that," John said. 

Sam cleared his throat. "Could we get back to the demon?" Clara nodded. “Thank you." 

"Like we said, we tracked it here from Salt Lake City. We don't know why it seems to have chosen to stop here, but it has," Dean said.

Castiel spoke up. "That means you are in a lot of danger, Sherlock. If the demon were to possess you, it would know everything you know, with potentially disastrous consequences, with your brother being who he is."

"Wait," John interrupted. "How do you know about his brother?"

"You think we'd let someone that important go without some sort of protection?" Dean asked. "You've met his assistant. Often goes by "Anthea"? She's one of us, a hunter of sorts." 

"Dean. Look at this."

Dean walked over to Sam and his computer, closely followed by Clara and the Doctor. Dean looked at the map on the screen that was overlaid with a mess of numbers, lines, and other symbols. "That's not good." 

"What? What's not good?" Clara asked. 

The Doctor spoke before either Winchester could explain. "It's raining quite a bit in Scotland."

"Yeah, that's normal, Doctor. It's autumn."

"Eastern Scotland. Rains, yes, but not this much. Too protected by the highlands."

"The Doctor's right," Sam said. "Weird weather is a sign of lots of demon activity. That and livestock deaths," he explained. "I've set my computer to track reports that might show us where our demon is."

"I remember something on the telly about that. Said it was some virus," John said. 

"I knew it wasn't a virus," Sherlock muttered. 

“No, you didn't. You just about bought a train ticket to go up there and diagnose it!"

Sherlock shot John a look. Sam cleared his throat. "Well, that's usually what the authorities think. Let's see..." He hit a few keys on the computer. "Look at this."

Dean looked at the screen. "Look at what? There's nothing there." 

"Exactly. There hasn't been a single report of dying livestock for... Two days."

"Since we got here."

"So, what now?" John said. "The demons were here and now they're gone, so we can all throw a big party and go home."

"Um... Not quite," Dean said.

"We have reasons to believe that the demon--"

"Or demons."

"...Are still here. And that they've targeted you, Sherlock."

"They're not here. Nobody has changed," Sherlock said.

"Are you sure? I mean, they--"

Sherlock cut Sam off with a look. "I am the greatest detective in the whole of England, and probably the world, and you ask if I'm sure?"

"Humble, aren't you," Clara remarked.

"You should have seen him at the Palace," John replied.

Sam cleared his throat. "We know this particular demon likes to –"

A symbol suddenly popped up on Sam's computer. "What's that?" Clara interrupted, pointing to it. 

Sam turned back to look. "That is... Crap. That is not good. Actually, no, it is good. It's saying there's a high possibility of a powerful demon, or group of demons, being there." 

"Yeah, we need to move quickly. You and you stay here with Cas," Dean said, pointing at Clara and Sherlock. "Sorry, but you'll get in the way."

Clara was about to object when the Doctor interrupted. "I need her. She's coming."

"And you'll need Sherlock, too. You want me along, you'll have to put up with him, too,"

Dean and Sam exchanged a look. Dean sighed. "Well, you can't all fit in the rental, so..."

"We'll take the TARDIS," Clara said matter-of-factly. 

"Sorry, the what?" Dean said skeptically. 

The Doctor sighed. "If you had listened earlier–"

"We'll show you," Clara interrupted. "Sam, you're the one who called the Doctor, right? You probably already know all about it. The rest of you though... Well, you'll just have to come see." And with that, she crossed the room, opened the door, and started down the stairs. A second passed, and she popped back into the room. "Well? Coming or not?" She looked at the unmoving and seemingly oblivious Sherlock seated at his microscope. "That includes you, too, smart boy."

Eventually Clara managed to get everybody downstairs standing in front of the big blue police box. "I'm sorry, I am not getting in that. There is no way that's going to fit all of us," Dean said, turning to go back upstairs. Sighing, Clara walked to the doors and opened them. Dean turned back. "Look, just because you're going in there doesn't mean I'll..." His voice trailed off as he tried to process what his eyes were seeing. "I... It..."

"It is bigger on the inside," Cas observed.

"Really? Never heard that one before," the Doctor said to himself. 

Sherlock slowly walked up to the machine, touched it, walked around it once, and then walked inside, carefully observing everything was he went. After a moment or two inside the ship, he came back outside and stared at it for almost a minute. Finally, he said, "Dimensional shift?"

John laughed in disbelief. "That's all you have to say? That it's science? There's an obsolete police box sitting there that's who knows how many times bigger on the inside than the outside and that's all you say! 'Dimensional shift'?" 

Clara cleared her throat. "Could we all just get in and go find the demon or whatever it is? You said it was urgent."

"I've got the coordinates right here," Sam said, "if there's somewhere I can, uh, input the numbers?" He stared at the center column and its wide array of devices attached, completely befuddled.

Sighing, the Doctor grabbed the computer out of his hands and set it on the console. Then, he knelt down and reached under the console, eventually finding the chord he was looking for. Pulling it out, he plugged one end into the computer and the other into one of many unidentifiable plugs in the TARDIS's console. As soon as everyone was inside and the door was closed, he hit a few buttons, pulled a lever, and the TARDIS took off. A minute later, it landed once again with a quiet wheeze.

Clara confidently strode over to the door and opened it to see... The same hallway they had just left. Quickly, she closed the door again and went over to the Doctor. "Are you sure you put the coordinates in correctly? Because that is exactly the same hallway we started at."

"Something must be wrong with the..." The Doctor trailed off as he went to go fix whatever was wrong.

"Doctor! Where do you think you're going?" she hissed after him. "At least tell everyone else what's going on!"

"That's what I've got you for! You tell them something."

"Tell them what exactly? That we'll have to take the Rental anyway because you don't know how to work your own TARDIS?"

"I don't know! Make something up! Lie! You're good at that."

"Doctor!" Clara was interrupted by someone behind her.

"If this is not working, I can transport people to the demon."

"Ah, no, Cas, you are not teleporting anyone over there," Dean interrupted. "Last time you tried that, we nearly got hit by a car and you were totally drained after. And that was just us two. No way you're doing that with everyone." 

"Sorry," Sam said, "but when exactly are we going to leave? This is kind of, you know, urgent, so if we could go? That'd be great."

"Right! Yes! Well, you're in luck because as well as being a space ship, it's also a time machine and can take us there at the exact time your computer picked up the signal! So, there's no need to worry, because the Doctor is just making sure he's getting us there right when we need to be there. The TARDIS is very precise and can land us within seconds of when we need to arrive–"

"You are a fantastically terrible liar," Sherlock interrupted. "The Doctor put in the coordinates, but his useless machine took us to the wrong spot, so now he's trying to fix it. With very little success I might add."

"Ah, well, yes," Clara said, "he did put in the coordinates, but sometimes they are a touch off. Should be back working in a minute. But like I said. Time machine!"

At that, the Doctor bounded back up the stairs, input a few numbers, spun a wheel, pulled a lever, and once again, they took off to go find the demon.


End file.
